Automated Patient Positioning Guided by Cone-Beam CT for Prostate Radiotherapy

摘要

Target localization, especially for soft-tissue target such as prostate, is a big concern in cancer radiotherapy due to its possible non-rigid internal motion relative to bony structures or external landmarks. The prostate target localization could be potentially done more accurately with the aid of the on-board kV cone-beam CT (CBCT) imager. In this project the PI group developed a novel technique of automatic patient positioning for prostate cancer radiation therapy. A few important milestones have been achieved toward the goal of the project. These include: (1) developed and clinically implemented an automated patient positioning strategy and tested with phantom experiments; (2) developed image-to-projection deformable registration algorithm to improve the CBCT image quality by reducing the view-aliasing artifacts; (3) established a novel technique to enhance on-board cone-beam CT and to effectively reduce the radiation dose incurred in the scanning process; (4) developed an innovative narrow shell technique for better target localization and model the critical structure; (5) established the method for auto-propagation of contours from planning CT to CBCT based on feature based spline deformable registration. The data and experiences we accumulated in this project are well documented, and server as a good reference for effectively utilizing CBCT imager, and will definitely enhance the outlook of the onboard CBCT in guiding radiation therapy as a whole.